Relay structure



Oct. 16, 1956 D. L. HALL ET AL 2,767,280

RELAY STRUCTURE Filed April 29, 1952 3 Sheets-5heet l D IJZjVENTORS.

0% YA/DWM @M/ D. L. HALL ET AL RELAY STRUCTURE Filed April 29, 1952 .3Sheets-Sheet 2 m m m m Oct; 16, 1956 D. HALL ET AL 2,767,280

RELAY STRUCTURE Filed April 29, 1952 3 Shee'ts-Sheet s United StatesPatent RELAY STRUCTURE Donivan L. Hall and Howard C. Stanley, Galion,Ohio, assignors to The North Electric Company, Gallon, Ohio, acorporation of Ohio Application April 20, 1952, Serial No. 284,972

18 Claims. (Cl. 200-87) This invention relates generally to a new andnovel relay construction and in particular to a relay construction whichis especially adapted for use with equipment which may in operation besubjected to severe accelerative and decelerative forces along one ormore of its coordinate axes.

With the constant advancement of the var ous industrial fields, numerousnew problems have arisen which have rendered the use of known types ofrelay structures somewhat impractical. in free flight equipment, such asaircraft, guided missiles, etc., the equipment s frequently exposed toshock and translational accelerauve forces in the order of at least 50gravities. Proper operation of the equipment under these conditions isdependent at least in part, upon the ability of the relay units forminga part thereof to withstand such forces withoutmechanical damage andwithout causing improper operation of their control contacts, i. e.,opening break contacts w th the coils deenergized and opening makecontacts with the coils energized. Further, the structure must be suchthat static and dynamic balance on all three coordinate axes of therelay are provided; that is, the relay contacts must be protectedagainst opening in response to translational acceleration along any ofthe coordinate axes; in any of the three planes determined by the threeCO-OIdll'lfile axes; and accordingly in any direction. The arrangementmust also provide means for protecting against improper contact openingin response to rotary acceleration in two of the three planes ofacceleration.

Since the available space for equipment used in aircraft is normallyextremely limited, the relay units must be comparatively small instructure and in many cases must be adapted to fit Within a space ofapproximately one cubic inch. The relays must further be of the typewhich lends itself to ready hermetic sealing, for failing suchconstruction, a relay is short lived in most aircraft applications. As aresult of the extremely limited space available for the relay unit aheat dissipation problem created which must be dealt with in order toinsure long relay life when used under these extremely adverseconditions.

Other conditions to which the relay must necessarily lend itself are:temperature compensation in constant voltage applications; mechanicalfunctioning of the relay over temperatures ranging from minus 55 C. toplus 85 C. in some applications and to plus 110 C. in otherapplications; a range of operating characteristics in the lower wattageoperating supersensitive type to the higher wattage operating lesssensitive type; ability to withstand 10 to 60 cycles per secondvibration at .060" excursion without mechanical damage and withoutaffecting operating characteristics; adaptability for use with one or aplurality of transfer contacts, the contacts being able to carry threeamperes interrupting current at 30 volts; and ability to withstand apotential to frame of 1000 volts R. M. S. and a minimum potential of 500volts R. M. S. between separated contacts.

2,767,280 Patented Oct. 16, 1956 While certain types of known relays aresuch as to permit modification thereof sufiiciently to satisfy certainof these foregoing requirements, the inherent design of the basicstructure of the relays known heretofore has been such as to negativethe possibility of providing a relay that would satisfactorily operateunder the adverse and severe conditions set forth. It is a primaryobject of this invention to provide a new basic armature, contact andcontact actuator arrangement which lends itself to ready inclusion inrelay structures of all types and which inherently permits the provisionof relay structures which are adapted to meet the most exacting ofspecifications and conditions of operation.

It is a further object of this invention to provide a plurality of newrelay structures including the new basic armature, contact and contactactuating arrangement, which fulfill the answers to the problemsexisting in many fields. It is a further object of the invention toprovide improved relays of comparatively small size which are adapted toresist acceleration and shock forces in the order of at least 50 gravityunits.

Other objects and advantages of the invention will become apparenthereinafter.

In order to acquaint those skilled in the art with our invention, weshall describe, in connection with the accompanying drawings, preferredembodiments of our invention and preferred modes of constructing thesame.

In the drawings, wherein like reference numerals refer to like parts:

Figure l is a side elevation of one embodiment of the relay of thepresent invention;

Figure 2 is an end elevation of the relay;

Figure 3 is a top plan view of the relay, with portions broken away toreveal the armature and the means operatively connecting the armatureand the pileups;

Figure 4 is a partial vertical section, on an enlarged scale, of thearmature mounting, the view being taken substantially on line 4-4 ofFigure 3;

Figure 5 is a side view, partly in elevation and partly in section, of acoil spool and core;

Figure 6 is a plan view of the coil spool and core shown in Figure 5;

Figure 7 is a perspective view of the novel basic armature, contact, andactuator arrangement of the present rnventlon;

Figure 8 is a top plan view of a modified embodiment of the relay of thepresent invention, the relay including four movable contact carryinglevers, a portion of the upper members of the relay being broken away toshow the mounting of the levers;

Figure 9 is a side elevation of a still further embodiment of theinvention, including adjustable means for calibrating or adjusting therelay;

Figure 10 is a top plan view, on a reduced scale, of the relay ofFigures 1 to 6, mounted in a casing, the casing being shown in section;

Figure 11 is a side view of the relay structure of Figure 10, the casingbeing shown in section;

Figure 12 is a view similar to Figure 10 of a second embodiment of acasing for the relay shown in Figures 1 to 6; and 1 Figure 13 is a viewsimilar to Figure 8 of the embodiment of the invention shown in Figure12.

Referring now to the drawings, the basic arrangement of armature,contacts and actuator is shown in Figure 7 as including an armaturemember 54 mounted in a given plane for rotational or oscillatorymovement about its central axis on a pivot pin 5256 with the applicationof given forces to the armature at points on opposite sides of thecentral axis of the armature, which points are equidistant from thecentral axis of the armature,

a contact carrying blade or lever 74 disposed on either side of thearmature plane and equidistant therefrom, and contact actuator means inthe form of a pair of levers 190 terminating in finger portions 106engaging the contact levers 74 for operating or moving the levers 74upon movement of the armature 54, the actuator means wit-106 beingmounted with the armature 54 and the contact carrying levers 74 in astatic and dynamically balanced manner. As pointed out, given forces areapplied to the armature 54 at points on opposite sides of the centralaxis of the armature. In one direction of pivotal or oscillatorymovement, the armature 54 is magnetically attracted to the pole faces 38of a pair of coil cores 24 and 26. The pole faces 38 of the cores 24 and26 are disposed in substantially parallel relation to the faces of thearmature 54 and the cores 24 and 26 exert equal magnetic forces on thearmature 54 to maintain the static and dynamic balance referred tohereinbefore. In the other direction of pivotal or oscillatory movement,the armature 54 is biased away from the pole faces 33 of the coil cores24 and 26 by means of a pair of springs 66, each of which is confinedbetween the juxtaposed faces of the armature and the cores 24 and 26respectively. The springs 60 exert equal forces on the opposite ends ofthe armature 54 so that the same maintain the static and dynamic balanceof the relay. Since force is applied to the armature at points spacedequidistant from the pivotal axis of the armature, since the contactcarrying levers 74 are spaced equidistant from the pivotal axis of thearmature and since the lever arms tilt) of the actuating means are ofthe same length and have the same disposition with respect to thepivotal axis of the armature 54, it will be appreciated that thearmature 54 and the contact carrying levers 74 are statically anddynamically balanced in all three axes of movement, that is, of movementexternally imparted to the relay arrangement. Accordingly, the contactlevers 74 and the armature 54 will not he accidentally orunintentionally actuated in response to extreme acceleration and shockforces.

As is shown in Figure 7, the levers 74 have overtravel with respect tothe stationary contacts of each contact set or pile up. This is a veryimportant feature of the present invention in that the overtravelinsures pressure engagement of the contacts and the maintenance ofcontact engagement despite external application of force to the relay.Due to the balanced relationship of the movable components of the relay,the possibility of accidental movement thereof is substantiallyminimized. However, should acceleration and/or shock forces of suchmagnitude as to impart movement to the armature 54, the levers 1M andthe contact levers 74 be suffered by the relay, the overtravel of thelevers 74 will accommodate slight movement of the levers and associatedcomponents to absorb the shock and minimize the possibility ofdisengagement of the contacts, or accidental or unintentional actuationof the relay. As will be described in detail hereinafter, contact leverovertravel may be provided in both positions or limits of armatureactuation to maintain at all times the advantages stated.

As was pointed out hereinbefore, the basic relay armature, contact andactuator arrangement provided by the present invention is adapted forutilization in a wide variety of types of relay structures and while wewill disclose hereinafter certain preferred embodiments of completerelays in accordance with the present invention, it will be appreciatedthat the invention is not limited in application to the specificembodiments disclosed herein.

Referring now particularly to Figures 1 to 6, one embodiment of therelay of the present invention is shown as including a pair of coils and22, each provided with a core 24 and 26 respectively. Basically, thecoils 20 and 22 are conventional spool type coils having a central coreincluding portions projecting to either side of the spool. The cores 24and 26 are formed of a permeable iron and, as shown in Figures 5 and 6,each comprises a generally cylindrical central portion 23 carrying apair of spaced discs or spool heads 3% formed of an insulating orplastic material, such as Bakelite. Disposed on the inner side of eachof the spool heads 39 is a spool head washer 32 suitably formed ofcellulose acetate or the like. The central cylindrical portion 28 of thecores 24 and 26 is suitably covered by an insulator, also preferablyformed of cellulose acetate or like material. At the lower end thereof,the core is provided with a reduced extension 36 and adjacent the upperend thereof, the core is slabbed off, as at 33, to provide a flat poleface. Preferably, the core is cut away at the portion thereof extendingupwardly from the upper surface of the top spool head 39 so as topresent a substantially semicircular pole piece. The pole piece isreduced at its upper end, as at 46, to provide a mounting stud, as Willbe explained in greater detail hereinafter.

The pole portion of each core is provided with a bore 42 therein adaptedfor the reception of a spring or the like, as will be explainedhereinafter. If desired, a residual member 44 may be associated with thepole portion of each of the coil cores. The residual 44 preferablycomprises a generally U-shaped clip adapted to he slipped over thesemi-cylindrical portion of the coil core and is formed of non-magneticor non-permeable material, so as to establish a minimtun air gap toenable the predetermination of the release current of the relay by othermeans, as will be described. It should be understood that plating of thearmature 54 and the pole piece portions 38 of the cores 24 and 26prevents sticking of the armature to the pole pieces independently ofthe residuals 44. The residual 44 is provided with an aperture in thecentral portion thereof which coincides with the bore 42 provided in thepole piece portion of each core.

The coil spools, formed in accordance with the foregoing, may besuitably wound with either conventional or heat resistant insulated typeof wire according to stand ard procedure to provide coils adapted forvarious particular purposes.

The reduced extension 36 at the lower end of each coil core is suitablypress-fitted or staked into an aperture provided adjacent each end of acrossbar or bottom strap 46 formed of magnetic or permeable iron. Thecrossbar 46 physically and magnetically connects the lower ends of thecoil cores 24 and 26 and retains the cores and coils in spaced parallelrelation, with the axes of the cores being substantially coextensive andlying in a common plane. At the upper end of the coils 2t) and 22, thecoil cores 24 and 26 are connected together by means of a pivot yoke 48comprising a U-shaped strap having a semi-circular aperture providedadjacent each end thereof adapted for the reception of the upper slabbedoff portion of the coil cores. Preferably, the pivot yoke 43 ispress-fitted onto the pole portions of the coil cores so as to bemaintained in intimate engagement with the upper surfaces of the spoolheads 30. The pivot yoke 48 is preferably formed of a non-magnetic ornon-permeable material such as nickel silver or brass, and is providedwith integral depending side walls 50 straddling the coils 20 and 22.The side walls 50 of the pivot yoke 48 extend in spaced parallelrelation to the common plane of the coil core axes. Each side wall 50 ofthe pivot yoke 48 is adapted for the reception of a contact assembly orpile-up, as will be described in detail hereinafter.

The crossbar 46 and the pivot yoke 43 mount the coils 2t) and 22 withtheir axes in spaced parallel relation, as pointed out hereinbefore.Intermediate its length, and centrally between the axes of the cores 24and 26, the pivot yoke 48 is provided with an aperture adapted for thereception of a pivot pin or axle rivet 52. The pivot pin 52 ispreferably formed of nickel silver and is spotwelded or staked to thepivot yoke 48. The pivot pin 52 is adapted for reception within anaperture provided in an armature 54. The armature 54 comprises agenerally rectangular block or slab of magnetic iron and is provided atthe upper edge thereof with an aperture adapted for the reception of apivot pin or axle rivet 56 which may be suitably spot welded or stakedto a top binder or strap 58. The pivot pin 56, like the pivot pin 52, ispreferably formed of nickel silver or the like. If desired, the pivotpins may be secured to the armature rather than to the yoke and binder.As is shown in the drawings, the pivot pins 52 and 56 are disposed onthe vertical central axis of the armature so that the armature isbalanced about its pivotal mounting. References herein to the centralaxis of the armature are to be considered as referring to the pivotalaxis thereof wherein the balanced relationship stated is maintained. Thetop binder strap 58, like the pivot yoke 43, is preferably formed of anon magnetic or non-permeable material, such as nickel silver or brass.The top binder strap 58 is provided adjacent the ends thereof withsubstantially semi-circular apertures adapted for the reception of themounting studs 4!) on the coil cores so that the straps may bepress-fitted onto the upper ends of the pole portions of the cores 24and 26 to connect the upper ends of the cores and to provide a pivotalmounting for the armature 54.

The armature S4 is preferably disposed at an angle to the plane of theaxes of the cores of the coils and 22, and the pole faces 33 of thecores 24 and 26 are preferably disposed at approximately the sameinclination in juxtaposition to the end portion of the armature 54.Resilient means in the form of a spring 60 is received within the borein each of the pole pieces and is confined between the pole piece andthe adjacent face of the armature 54 so as to normally bias the armature54 away from the pole pieces of the cores 24 and 26.

On the opposite sides of the plane of the coil axes, the side walls 5bof the pivot yoke 48 are adapted for the reception of a pair of contactassemblies or pileups, indicated generally at 62. The pile-ups 62 eachcomprise a generally rectangular side plate 64, formed of Bakelite,glass silicon, or suitable like insulating material, mounted or securedto the side walls 50 of the pivot yoke 48 by means of suitablefasteners, in the form of rivets 66. Each side plate 64 carries a firststationary contact support 68, a contact 69 carried thereby, a secondstationary contact support 7t), a contact 71 carried thereby, a pair ofmovable contacts 72 mounted on opposite sides of a lever 74, includingan integral mounting tab 76, and a coil terminal 78. The stationarycontact supports 63 and 70 preferably comprise generally L-shaped platesformed of phosphorous bronze or the like having one leg thereof securedto the side plate 64 and adjacent the upper end thereof by means ofsuitaoie rivets 80. An apertured tab is formed integrally with each ofthe one legs, the tabs being adapted for the reception of suitable leads82 and 84, respectively. The second legs of the plates extend outwardlyof the plate 64 in spaced parallel relation to one another, and wherebythe upper contact bearing end of lever 74 may extend therebetween. Thecontact bearing lever 74 is preferably formed of an alloy known asBerylco and is secured to the side or mounting plate 64 by means ofsuitable rivets 36 extending through the tab 76. The tab 76 preferablyincludes an apertured end portion adapted for the reception of asuitable lead 88. The contact lever 74 carries a pair of contactssuitably welded or otherwise secured to opposite sides of the blade anddisposed adjacent to but spaced from the upper end thereof. Insulatingmaterial 90, which may comprise a strip of a glass base tape, a glassysurface, or the like, is attached to the upper end of the blade toinsulate the lever blade 74 from an associated operating arm 1430. Asshown in Figure 9, the insulating members may be an integral part of theoperating arm 100, this modification being set forth in more detailhereinafter. Adjacent the upper end thereof, the blades 74 arepreferably notched, as at 92, so that the two legs of the insulatingtape 90 may be suitably glued or otherwise secured to one another.

The coil terminal 78 is preferably formed of ph0sph0rous bronze or likematerial and may be suitably secured to the lower end of the side ormounting plate 64, in spaced relation to the mounting tab 76 of thecontact blade 74, by means of a plurality of rivets 94. The coilterminal 78 is preferably provided with an integral tab portion havingan aperture therein adapted for the reception of a suitable lead 96. Therivets 94, and the remainder of the rivets utilized in the constructionas described, are preferably annular in form, and the rivets 94 areadapted for the passage therethrough of a suitable lead 98 for one ofthe coils 20 and 22. The coils 20 and 22 are preferably seriesconnected.

The axes of the coils 20 and 22 are disposed in a common plane, whichplane comprises one major dimension of the relay of the presentinvention. The pile-up 62 are mounted in spaced parallel relation toopposite sides of the common plane of the axes of the coils 20 and 22and each include a contact blade 74 disposed in spaced parallel relationto one another, to the axes of the coil cores 24 and 26 and to the planeof the axes of the coil cores 24 and 26. The contact blades 74 aredisposed in a common plane which extends transversely of and generallynormal to the plane of the coil core axes and intersects that planesubstantially intermediate or centrally of the coil core axes. Thissecond plane, namely, the plane of the contact blades 74, comprises theother major horizontal dimension of the relay, as will be apparent froma consideration of Figure 3. The axis (horizontal) of each set ofcontacts, 69, 71, and 72, extends generally parallel to the plane of thecoil cores 24 and 26 and generally normal to the piane of the contactblades 74. As will be apparent, the principle axis of each of thepile-ups 62 comprises the longitudinal axis of the movable contactblades 74, and accordingly, as utilized hereinafter, the axis of eachpile-up 62 is to be considered as the longitudinal axis of the movablecontact blade or lever 74.

As will be apparent from a consideration of Figure 3, the armature 54 ispivoted upon an axis defined by the line of intersection of the planesof the coil core axes and the pile-up axes, which line of intersectionlies intermediate or centrally of the two coils and the two contactassemblies or pile-ups. As is also shown in Figure 3, the armature 54has a longitudinal axis inclined to both of the hereinbefore definedplanes and the end portions of the armatures are juxtaposed to the polefaces 38 of the coil cores are disposed at approximately the same angleof inclination as is the armature 54.

Adjacent the central portion thereof, the armature 54 suitably carries apair of levers 100, each extending transversely and outwardly thereof.The levers 100 may be disposed as desired with respect of the armature54. but same preferably extend to the opposite sides of the armature andsubstantially normal to the longitudinal axis of the armature. Thelength of each lever 100 is preferably approximately equal to one-halfthe length of the armature 54. The levers 100 are preferably formedintegrally in a unitary steel stamping consisting of the levers 100 anda central portion 102, including a pair of tabs 104. The tabs 104 areadapted to be turned over and engage the opposite sides of the armature54 and may suitably be spot welded thereto as shown in Figure 3, each ofthe levers 100 may be suitably spaced from the pivot axis of thearmature S4 and the central portion 102 of the lever stamping isprovided with an aperture adapted for the passage of the pivot pin 56.At the outer end thereof, each lever arm 100 includes a generally 0-shaped finger portion 106 adapted to engage the extending upper portionor end of the respective contact blade 74. As will be apparent from aconsideration of Figures 1 and 2, the contact blades or levers 74 eachextend upwardly beyond the upper end of the coils 20 and 22 and beyondthe upper end of the stationary contacts 69 and 71 and their mountings68 and 70 so as to be adapted for engagement by the finger portions 106of the levers 100. The finger portions 106 of the levers 100 engage theop- 7 posite sides of the contact blades 74 in substantially intimaterelation so as to insure responsiveness of movement of the contactblades, the levers and the armature.

While the finger portions 106 of the lever arms 1% are referred toherein as generally C-shaped, it will be appreciated as the descriptionproceeds that any actuator means presenting juxtaposed portions adaptedfor the intimate reception therebetween of a contact carrying blade inan interlocking manner is to be considered as the equivalent structure.

The stationary contact supports 68 and 7t consist of relatively shortpieces of stiff material to provide a substantially rigid mounting forthe contacts 69 and 71. The springs 60 confined between the coil polesand the armature normally exert bias forces at the ends of the leverblades 74 of su fiicient magnitude to cause the lever ends to travelbeyond the position where contacts 69 and 72 are engaged. Contacts 69and 72 are thereby engaged with one another under substantial pressureto insure good electrical contact therebetween and with lever endovertravel to provide shock and acceleration resistance, since slightmotion tending to open the contacts 69 and 72 is permissable within thelimits of said overtravel.

Upon energization of the coils 20 and 22, the armature 54 is attractedtoward the pole faces 38 of the coil cores 24 and 26 and is moved intoengagement or contact therewith against the normal urge of the springs60. Upon movement of the armature 54, the levers 10%, due to theirdisposition with respect to the pivotal axis of the armature, move thecontact blades 74 toward the stationary contacts 71, the motion of thearmature 54 being transmitted by the levers 100 so that the ends of theblades 74 are moved to an extent greater than that required to merelyeffect engagement, whereby overtravel of the blade ends is accomplished.Contacts 71 and 72 are thereby engaged with one another undersubstantial pressure to insure good electrical contact therebetween andwith lever end overtravel to provide shock and acceleration resistance,since slight motion tending to open the contacts 71 and 72 ispermissable within the limits of said overtravel.

Upon energization of the coils and 22, the magnetic path through therelay is established through the cores 24 and 26 of the coils 20 and 22,respectively through the bottom strap 46, through the armature 54 andthrough air gaps between the ends of the armature and the pole faces.The remainder of the structural elements of the relay are preferablyformed, as stated hereinbefore, of non-magnetic or non-permeablematerials so that there is a high degree of flux concentration betweenthe pole faces 38 of the cores 24 and 26 and the armature 54. To be ableto control the release current of the relay, it may be desirable in manyinstances to employ the residuals 44.

The spacing or contact gap between contacts 71 and 72 in thenon-operated position in the pileups 62 is approximately .008". Themounting members for the stationary contacts are preferably of asubstantially rigid nature so that there is no movement of the contactsfrom their normal disposition despite extreme acceleration anddeceleration.

It will be clear that upon deenergization of the coils 20 and 22, thesprings 60 will return the armature 54, the levers 100 and the contactblades 74 to their original or normal positions and that there will beno tendency of the armature to become magnetically locked or otherwisestuck.

The complete relay assemblies of the present invention include the basicarrangement described hereinbefore with respect to Figure 7. Generallyspeaking, this basic relay arrangement or relationship may be stated inanother manner as was described with reference to Figure l to 6, ascomprising a pair of poles having spaced parallel axes lying in a commonplane, a pair of pileups having spaced parallel axes lying in a commonplane, the two planes bisecting one another and being preferablysubstantially normal to one another, an armature mounted on an axisdefined by the line of intersection between the two planes so that forcewill be applied to the armature at points equidistant from the pivotalaxis thereof, and a pair of lever arms for connecting the armature andthe pileups, the movable contact carrying blades of each pileup havingovertravel with respect to the stationary contacts thereof. As will beappreciated from the foregoing description, the pole faces of the coilcores are preferably disposed parallel to the armature faces. In thepreferred construction of the relay of the present invention, the axesof the coil cores and the axes of the pileups, that is, the axes of themovable members of the pileups, are all disposed equidistant from thepivotal axis of the armature so that optimum static and dynamic balancewill be obtained. However, it will be appreciated that since the planesof the pileup axes and the coil cores axes bisect one another that therelay will be balanced even through the axes of the pileups are notdisposed the same distance from the pivotal axis of the armature as arethe axes of the coil cores.

Referring now to Figure 8, another embodiment of the present inventionis shown wherein the pileups are of a somewhat different constructionand each include four stationary contacts and a pair of movable contactcarrying levers or blades. In the relay construction shown in Figure 8,the pileup mounting side plates 64 are omitted and a horizontal mountingplate 264 is substituted therefor.

A pair of slots 266 are formed in the mounting plate 264 from oppositesides thereof to accommodate the passage therethrough of the contactcarrying lever assemblies 275 of the respective pileups. If desired, themounting plate 264 may be provided in halves, in which case the halvesare spaced apart to provide the slots 266 for the passage of the leverassemblies 275. For purposes of description hereinafter, the mountingmeans of the embodiment of the invention shown in Figure 8 will bereferred to as a single mounting plate 264 provided with slots 266, asis preferable. The plate 264 is secured in position by means of asuitable strap or hinder 267 press-fitted on th cores 2? 26 of the relaycoils. The mounting piate 26 like the mounting plates 64 of theembodiment of the invention previously described, may be formed ofBakelite, glass silicon, or like insulating material. and is adapted forsupporting a plurality of stationary contact supports. As shown inFigure 8, each pileup includes a first pair of stationary contactsupports 268, each carrying a stationary contact 269, disposed to oneside of the slot 266 in the mount ing plate and a second pair of contactsupports 270, each carrying a contact 271, disposed to the opposite sideof the slot 266 in the mounting plate. Each of the stationary contacts269 is aligned with one of the stationary contacts 271 and the movablelever assembly 275 includes a pair of contact carrying levers 274, eachcarrying a pair of contacts 272 adapted to engage respectively with thestationary contacts 269 and 271 of each set of stationary contacts. Thelevers 274 of each lever assembly 275 are connected to one another forconjoint actuation by means of suitable insulating strips 277. At thelower end thereof, the contact carrying levers 274 are each providedwith an integral tab 276 by means of which electrical connection may beestablished. Adjacent the lower end thereof, the levers of each assemblyare secured to a mounting strip 279, formed of insulating material,which mounting strip is secured to a bar 279, suitably secured to, orformed integrally with, and extending transversely of the bottom crossbar of the relay.

While the pileup arrangement of the embodiment of the invention shown inFigure 8 is somewhat different from the pileup arrangement previouslydescribed, it will be apparent from the foregoing that the principalaxis of each pileup comprises the longitudinal axis of the leverassembly 275 and that the axes of the lever assemblies 275 are disposedin spaced parallel relation to one another and to the axes of the coilcores 24 and 26, with the coil core axes lying in a common plane and theaxes of the lever assemblies 275 lying in a common plane, which planesbisect one another and define at their line of intersection the pivotalaxis for the armature 54. Accordingly, it will be appreciated that thebasic arrangement described hereinbefore is the basis of design for therelay shown in Figure 8. The embodiment of the invention shown in Figure8 discloses the provision of multiple contact unit pileup assembliesutilized in relays having the basic arrangement of the presentinvention. While two contact sets have been shown in each pileup inFigure 8, it will be appreciated that the number of contact sets in eachpileup assembly may be varied as required or desired for variousinstallations.

The actuator means for operatively connecting the pileups and thearmature 54 of the embodiment of the invention shown in Figure 8 may bethe same as the lever assembly or stamping described hereinbefore, inwhich case, the finger portions of the lever stamping would intimatelyengage the opposite sides of the strips 277 interconnecting the twolevers 274 of each lever assembly 2'75. However, a modified actuatorlever assembly has been shown in Figure 8 wherein the assembly includesa pair of lever arms 300, each terminating in a finger portion 366engaging the insulating strips 277 in tr e manner described. As shown,the lever as sembly comprises a unitary member with the axes of the twolever arms 360 being aligned and disposed at an angle of inclinationwith respect to the longitudinal axis of the armature 54. Thisarrangement does not affect the statically and dynamically balancedrelationship described hereinbefore, since the longitudinal axes of thepileups are still disposed equidistance from the pivotal axis of thearmature 54 and th lever arms 300 are identical in length and relativedisposition with respect to the armature. In respects other than thosereferred to specifically hereinbefore, the embodiment of the inventionshown in Figure 8 is substantially identical to the embodiment of theinvention shown in Figures 1 to 6, and enjoys the same advantages as thepreviously described embodiment of the invention and in addition theretoprovides a greater number of contact sets. It wil be appreciated,however, that, if desired, the embodiment of the invention shown inFigure 8 may be employed with a single contact set and a single contactlever in each of the pileups.

As has been previously pointed out herein, the basic relay arrangementprovided by the present invention lends itself to ready utilization inthe provision of many forms and types of relay embodiments. For example,the basic structural arrangement has been utilized in relay units havinga range of sensitivity in operation extending from the lower wattage(.005 watt at 20 C.) operating supersensitive type to the higher wattage(.375 at 20 C.) operating less sensitive type. It is noted that in theprovision of relays of greater sensitivity, the make and break contactsof the relay structure must be set with extremely close tolerances. Tomeet these conditions, the present invention contemplates the provisionof adjustable means for effecting the ready accomplishment of thesettings.

Referring now to Figure 9, an embodiment of the invention is shownwherein provision is made for fine adjustment of the tolerances involvedin (a) the makecontact follow and (b) the air gap between contacts. Itis of course apparent that from the standpoint of minimizing possibleinaccurate relay operation the foregoing two factors should be as largeas possible. On the other hand, the greater the make-contact follow, thehigher the release current will be because of the greater tensionimposed upon the lever spring. Also, as the make follow is increased,the operating current must be increased because of the greater openingof the armature air gap. Finally, increasing the contact gap willnecessarily increase the opening of the armature air gap and result in ahigher operating current. Since limits are necessarily placed upon theoperating and release current of the relay, extremely close tolerancesmust be maintained in the mechanical setting of the make and breakcontacts whereby a compromise between relay reliability and electricalcharacteristics may be readily accomplished. As is shown in Figure 9,wherein the relationship of the various relay parts and elements issubstantially the same as that shown in Figure l, the stationarycontacts 69 and 71 of each pileup are each mounted upon a set screw 369and 371, respectively, which set screws are each mounted for threadedadjustment on contact support members 368 and 37% respectively. Thecontact supporting members 368 and 37% are each fixedly secured to themounting plate 64 in much the same manner as the supporting members 68and 76 described hereinbefore, and each includes a leg portion extendingoutwardly of the plate 64 with the said leg portions of the contactsupports disposed in spaced parallel relation. Adjacent the outer endthereof, the extending leg portions of the contact supports 36% and 579are each provided with a tapped bore adapted for the threaded receptionof the set screws 369 and 371, respectively. To prevent accidental orunintentional movement of the set screws with respect to their supports,which would result in maladjustment of the relay, the supports 363 and37% are each provided at the outer edge thereof with a slot extendingthrough the body thereof into communication with the bore therein so asto provide flexible fingers engaging the respective set screw to exert aload thereon and lock the set screws in adjusted position. The slots areindicated at 375 and 377, respectively. In addition to the lockingfingers, the screws are cemented in place with an appropriate heatresistant, non-aging and non-flaking cement after final adjustment. Asis shown, each of the set screws 369 and 371 is provided with a suitablekerf to accommodate the insertion of a screw driver or a like tool foreffecting adjustment of the stationary contacts 69 and 71 carried by thescrews 369 and 371, respectively. As will be apparent, the relationshipof the movable contacts 72 and the movable contact carrying lever 74 isthe same as that described hereinbefore with reference to Figures 1 to6. However, whereas the movable contact carrying lever 74 was describedhereinbefore as provided with insulating means at the upper end thereofadapted to insulate between the contact lever and the finger portion ofthe actuating lever assembly, the embodiment of the invention shown inFigure 9 differs somewhat from that previously described. In particular,the finger portion 106 of the lever assembly terminates in a pair ofjuxtaposed fingers and a suitable bead 380 of insulating material isformed at the end of each of the fingers to provide an insulatedconnection between the levers of the actuating lever assembly and themovable contact carrying lever 74 of each pileup. The head 380preferably comprises a head of ceramic material or glass fused to thetips of each finger, but as will be appreciated, the beads may be formedin various other manners, such as by dipping the lever ends in a moltenbath of ceramic material or the like. As will be apparent from aconsideration of Figure 9, the upper end of the contact lever 74 isintimately received within the space defined between the beads 380provided on the fingers of the lever assembly so that the armature andpileups are operatively connected without lost motion therebetween.

Due to the strict tolerances which are rendered necessary by reason ofthe magnetic factors of the structure, means must be provided forcompensating for variations in spring tension. To this end, theembodiment of the invention shown in Figure 9 includes means for varyingthe force exertion of the springs 60, which bias the arma- 11 ture 54away from the coil cores 24 and 26, by varying the depth of the springhousing holes provided in the coil cores. To accomplish this variationin spring tension, the housing holes 42 provided in the coil cores areformed as continuous bores extending entirely through thesemicylindrical portion of the coil cores and substantially normal tothe pole faces 38 defined by the cores. These bores are then tapped soas to be adapted for the reception of a set screw from the side of thecoil core opposite the pole face 38 thereof, one such set screw beingindicated at 385 in Figure 9. As will be appreciated, adjustment of theset screw 385 will vary the tension of the springs 69 so as to providefor the proper adjustment and calibration of the relay. In addition toproviding means for compensating for variation of spring tension, theprovision of continuous bores in the coil cores for the reception of thesprings 6 and the provision of the set screws 385 for closing the boresaccommodates a more ready and convenient assembly of the relay. Inparticular, the armature assembly may be ac 'complished before thesprings are inserted in the holes or bores provided in the coil cores sothat the assembly of the armature on the pivot yoke 48 and the assemblyof the top strap 58 to the coil cores may be readily effected.Thereafter, the springs 60 may be conveniently and readily inserted inthe bores provided in the coil cores and the set screws 385 maythereafter be inserted and threaded into the bores of the coil cores toconfine the springs 60 between the set screws and the armature 54.Thereafter, the set screws 385 may be adjusted to provide for propersetting and calibration of the springs 69, after which the set screwsare cemented in place, as was described hereinbefore with respect to thecontact set screws.

A particular manner of effecting adjustment of the set screws for theback tension springs and the contacts is as follows: the power source isconnected to the relay to effect energization of the coils and theoperation of the armature to its operated position. The contact screw37-1 is then adjusted until the contact 71 just touches the lever springcontact 72. The make contact screw 371 is then advanced .003 inchi.0005inch and the break con tact screw 369 is then adjusted so that thedistance between the break contact 69 and its associated lever springcontact 72 is .008 inchi.0005 inch. The pole core screws are thenadjusted to vary the armature spring ten sion to a point where the relayoperates within specified limits such, for example, as 2.0 to 2.3 ma. inone embodiment of the invention. Upon attaining the proper adjustmentfor the energizing operation, the relay is released to determine whetherthe current is within certain predetermined limits, for example 1.0 to1.3 ma. in the said one embodiment. If the value of the release currentis too low, the make follow is increased or the actuator lever assembly106 is bent downward slightly so as to move the glass beads 380 to alower position on the movable contact carrying lever 74. If the releasecurrent is too high, the make follow is decreased or the glass beads38!) are raised.

The air gap distance between the pole piece and the armature effects theoperating current value. Furthermore, the amount of make follow effectsboth the release current value by the tension placed on the lever springand it also effects the operate current value by affecting the air gapdistance between the pole piece and the armature.

Lever spring overtravel is provided on both make and break contacts. Onbreak contacts the lever spring overtravel is accomplished by auxiliarysprings between the pole pieces and the armature, and made possible bythe combination of solidly positioned fixed break contacts and aflexible lever spring. On make contacts, the lever spring overtravel isactuated by the magnetic force exerted by the coil on the armature uponenergization of the coil and is made possible by the combination ofsolidly positioned 12 fixed make contacts and a flexible lever spring.The following ratio is maintained:

From lever spring support to contacts From lever spring support to otherend of lever 3 Due to the relative disposition of the coils, thearmature, the levers 109 and the pileups 62, the relay of the presentinvention is highly resistant, or nonresponsive, to continuousacceleration or sharp changes in velocity. In particular, therelationship of parts described hereinbefore renders the relay of thepresent invention insensitive or nonresponsive to accelerations :of theorder of at least fifty gravity units.

In addition to the advantages pointed out hereinbefore, the relay of thepresent invention readily lends itself to fabrications in extremelysmall sizes. Generally, it may be stated that the major horizontal axes,namely the axis along which the coil core centers lie and the axis uponwhich the contact blades lie, may be maintained fairly constant oruniform for many various installations for which the relay of thepresent invention is adapted. However, the length of the coils in theseinstances may vary within quite substantial limits to accommodate thewinding of coils adapted for energization from various sources and powersupplies. Normally, variations in the physical dimensions and structureof the relay may be required in adapting the same for variousinstallations, but the basic arrangement provided by the invention willbe adhered to. Despite these variations, the adaptability of the relayof the present invention may cover a wide variety :of installations,while the physical dimensions of the relay may vary only slightly, withthe exception of the length of the coils, which may be varied withinrelatively large limits. In particular, preferable dimensions for therelay of the present invention are: in the plane of the axes of thecoils 2t) and 22, the overall dimension of the relay is preferably fromM; inch to 1% inches; in the plane 'of the contact blades 74, theoverall dimension of the relay is preferably from inch to 1% inches; andthe height or length of the coils may be varied between inch and 1%inches. it is to be appreciated however, that the foregoing dimensionsare only exemplary and preferred dimensions and should not be consideredas necessarily restrictive of the present invention.

The relay of the present invention is adapted for utilization in a widevariety of installations and may be mounted within any suitablecontainer or casing for the particular installation for which adapted.However, in accordance with the present invention, it is preferred thatthe relay be mounted in a particular manner, and for preferredembodiments of the mountings or casings for the relay of the presentinvention, reference is made to Figures 10 to 13.

In Figures 10 and ll, the relay of the present invention is shown asmounted within a generally box-like casing comprising a rectangular baseplate 110, preferably formed of steel or the like, and a can-like bodyportion 1L2, preferably formed of brass, copper or aluminum hot tindipped. The casing of the embodiment shown in Figures 10 and 11, ispreferably substantially cubic, although the dimensions thereof may bevaried within any necessary limitations. The base plate 112 ispreferably square and the two major axes of the relay are preferably sodisposed with respect to the base that same extend along the diagonalsof the base so that the casing may be as small as possible.

The base plate 110 is preferably spaced from the bottom strap 46 of therelay by means of a pair of studs I 114 which are preferably formed ofbrass to physically face or top of the can 112 preferably engages thetop binder 58 of the relay and the lower free edges of the can arepreferably turned over the base plate and suitably soldered, welded orotherwise secured to the base plate so as to effect intimate engagementof the casing with the opposite ends of the relay. The soldering orwelding between the base plate 110 and the can 112 is preferablyeffected so that the relay may be hermetically sealed within the casingin a conventional manner.

As is shown in Figures 1 to 3, the top binder 58 for the relay may inmany installations comprise a generally rectangular strap or the like.When mounted in the can 112, the relay is confined against endwisemovement due to the engagement of the top binder 58 with the top wall ofthe can and the engagement of the bottom strap 46 with the studs 114.Sidewise movement of the relay is restrained by engagement of the coilspools with the side walls of the can. However, in installations whereinsubstantial side thrust is to be imparted to the relay, it is desirableto provide means for positively resisting sidewise movement of the relayin the can. In particular, according to the present invention, weprovide a generally octagonal top binder plate, indicated at 113 inFigures and 11, adapted to abut against the side walls and top of thecan to prevent movement of the relay within the can in any direction.While the member 113 has been referred to as a top binder, it will beapparent that the same may suitably comprise a plate secured to the topbinder 58. To provide for intimate engagement between the can 112 andthe top binder or member 113, the top edges of the can are squared off,as is indicated at 115. Accordingly, the can maintains the relay inoperating relationship at all times. Since the can 112 and base plate110 provide means for enclosing the relay to accommodate hermeticsealing of the relay, it may be further pointed out that the hermeticsealing means holds the relay together and maintains the same inoperating relationship.

The base plate 110 preferably carries a plurality of threaded mountingstuds 116 suitably secured to the base plate 110, as by beingspot-welded thereto. The base plate 110 also carries a header, indicatedgenerally at 118, fitted Within a central aperture in the base plate.The header 118 preferably comprises a cylindrical shell 120, a pluralityof terminals 122, and a molded vitreous seal 124 mounting the terminalsin appropriate manner within the cylindrical shell 120. The vitreousseal 124 is preferably formed by flowing molten glass into the shell 120and around the terminals 122. The terminals 122 may each comprise ahollow tube or the like adapted for the reception of a relay lead, whichleads are preferably soldered or otherwise secured in the terminal tubes122. It will be apparent that other types of terminals may be provided.To serve as a guide for Wiring the relay within a circuit, one of theterminals may be suitably marked, as by a colored disc 126, to define acoded starting point for determining the relay terminal connections. Aswill be appreciated, various details of the header and mounting studsmay be modified to provide for other types of mounting.

Due to the fact that the relay is formed almost entirely of metal anddue to the physical engagement of the relay with the casing, the casingand the studs 116 thereof serve as a heat exchanger for rapidlydissipating heat generated upon energization of the coils. This heatdissipation is further enhanced by the formation of the various parts ofthe relay and easing of highly conductive metals. The insulation 34provided between the coils and the cores is very thin (.006") so as topresent substantially no impedance to heat dissipation. In particular,heat generated during energization of the coils is dissipated bymaintaining a low temperature gradient between the interior of the coiland the exterior of the can by providing a heat conducting path from thecoil to the 14 exterior can. The heat generated by the coil in theillustrated embodiment is extended through the magnetic iron core,approximately .005" of cellulose acetate and the metallic contactmembers which extend from both ends of the core to the external can.

Referring now to Figures 12 and 13, a further modification or secondembodiment of a casing for the relay of the present invention is shown,wherein the casing is generally cylindrical. For cylindrical mountings,the relay is preferably provided with annular end plates to space andinsulate the relay from the casing. Pref erably, the relay is providedwith an upper circular plate adapted to be secured to the top binder ofthe relay by means of a plurality of rivets 152. The upper mounting orend plate 150 is preferably cut out, as at 154, to make accessible theupper extensions or upwardly extending end portions of the contactblades of the relay. The relay is also provided with a lower circularend plate 156 provided with a plurality of spaced apertures therein,preferably four in number to either side of the relay, adapted for thepassage of the relay leads. The end plates 150 and 156 are preferablyformed of Bakelite or a like plastic or insulating material. The casingfor the relay includes a cylindrical can 158 of greater length than therelay so that the relay may be inserted into the can and moved intoengagement with the top wall thereof, after which the casing may beprovided with a peripheral or annular indentation 160 engaging the lowersurface of the lower end plate 156 to retain the relay in the upperportion of the cylindrical can 158.

At its lower end, the can 158 is preferably flanged and adapted for thereception of a base plate 162. The base plate 162 preferably comprises aconventional octal base plate, comprising a circular metallic plateprovided with a plurality of apertures therein, the apertures beingdisposed in a circle about the central point of the base plate. Theapertures are each adapted for the reception of a terminal 164 suitablysealed within the respective aperture by means of a vitreous seal 166.The base plate 162 is also preferably provided with a central stud 168having a lateral projection 170 adjacent the lower end thereof so thatthe base plate comprises a mounting member of the general typeconventionally or popularly known as radio tube base. In this embodimentof the invention, the terminal members 164 preferably comprise hollowtubes each adapted for the reception of one of the relay leads, whichleads may be suitably soldered or otherwise secured Within th hollowterminal members. At the upper end thereof, the can 153 may be suitablyformed for the reception of a hermetic sealing tube 172 adapted to becut off and sealed, as is shown, after the relay has been assembledWithin the can. To accommodate the hermetic sealing tube and thehermetic sealing of the relay Within the can 158, the upper end plate150 is preferably provided with a central aperture therethrough. As willbe appreciated, the can 112 of the embodiment of the invention shown inFigures 10 and 11 could likewise be provided with suitable means toaccommodate hermetic sealing of the relay within the can.

indicative of the different types of relay members which may be providedutilizing the basic structure set forth heretofore are the followingspecifications of proven commercial embodiments.

in a first relay arrangement having maximum sensitivity, that is,responsive to a very low value of wattage, coils of 40,000 turns of No.39 wire with a total resistance of 5000 ohms were provided and theoperation thereof was effected with the application of .005 watt at 20C. The power supply in this case was comprised of a constant currentsource. The relay operates on .001 to .0011 ampere and releases on .0003to .0007 ampere. In an arrangement having constant current power supply,an increase of temperature raises the resistance of the coils and thewatts used increases with the temperature. However, whenever only anincrease of about 20% occurs up to 85 C., and with a decrease intemperature below C. less watts are required for relay operation. Therelay occupied approximately 1% cubic inches and was mechanicallyoperable from minus C. to plus 110 C.

In a second model of slightly less sensitivity (responsive toapplication of slightly greater value of wattage) coils of 35,000 turnsof No. 42 wire with a total resistance of 5,000 :ohms were provided andoperation was affected at .02 watt at 23 C. The relay structure wasoperated on .002 to.0025 ampere and released on .001 to .0015 ampere.The power supply was of the constant current type and only an increaseof about 20% occurred up to C. The relay of the present embodimentoccupied a space of 1" x 1" x 1%".

A relay model of nominal sensitivity, that is responsive to a slightlyhigher value of wattage utilized coils having a total of 46,000 turns ofNo. 43 wire with a total resistance of 11,000 ohms. The relay operatedat .05 watt at 20 C. with a constant current supply. This relayincorporates an extra set of contacts without requiring a housing largerthan that of the previous relays.

In the relays adapted for use with constant current supply sources, thecontrol circuit maintains the current constant independent oftemperature and hence no temperature compensation is necessary. Inrelays adapted for use with constant voltage structures, however,temperature compensation must be provided. That is, in a constantvoltage application the coil resistance rises with a rise in temperatureand the current decreases. If the relay is to perform within a givenrange of temperatures, temperature compensation must be provided. In oneembodiment in which the relay was built to operate from a constantvoltage source of 26.5 volts, the structure was built to permit enoughcurrent for operation at 68% of nominal voltage, that is, on 18 volts at85 C. Thus with rising temperature and reduced current proper relayoperation is insured. The relay consumed .720 watt based on 450 ohm coilresistance at 20 C. With decreasing temperature at constant voltage, thecurrent increases and the relay receives enough current to operate atany value below +85 C. Although the current and the wattage increasewith decreasing temperature, the lower ambient temperature protects therelay against overheating.

The relay must also be adapted to withstand 123% of nominal voltage,that is 32 volts at 85. The equivalent of this value (18 volts at 85 C.)is obtained with a factor of safety by adjusting the relay so that itjust operates on ten volts at 20 C. corresponding to .375 watt.

In this embodiment the coils comprised 6,000 turns of No. 39 wire with atotal resistance of 450 ohms. The relay Was mechanically operablebetween 55 C. to C. The relay structure included two sets of transfercontacts and required a mountin space of .72 cubic inch.

A relay of less sensitivity but having the same specifications of therelay just described may be provided with four sets of transfer contactsand a housing space of 1" x 1" x 1% is then required.

Heretofore, it has been extremely difiicult to provide relays adaptedfor operation at high temperatures due to the fact that a. definite setof the contact carrying springs or levers has been required in priorrelay structures. The difiiculty has existed for the particular reasonthat metals having a sufficiently high electrical conductance to serveas contact carrying levers do not possess the mechanical characteristicof'maintaining a set at elevated temperatures, and that metals havingthe latter characteristic do not possess the necessary degree ofelectrical conductivity. The present invention obviates the difficultyby providing a novel relay arrangement wherein the various componentsare not required to meet conflicting specifications. In particular, thenecessity of providing a set in the contact carrying levers has beenobviated by providing the biasing springs 60 which eifect high pressurecontact engagement and contact lever over-travel. Since the contactcarrying levers need serve only as electrical conl. 5 ductors and sincethe biasing springs need only maintain a predetermined set, neither ofthe two components is required to perform the conflicting function ofthe other, whereby the relay is adapted for use at elevatedtemperatures. In particular, the relay design described hereinbefore isreadily adapted for high temperature applications, such as 200 C.,merely by utilization of high temperature resistant insulatingmaterials. For example, the substitution of glass based silicon forBakelite, Ceroc-T for Formvar and porcelain for glass, will render therelay previously described adaptable for operation and use up to atleast 200 C.

It is to be understood, of course, that while the aforementionedspecific relays have been described to teach certain of the embodimentswhich may be provided with the novel relay structure of the invention,it is to be appreciated that the degree of sensitivity and temperaturerange of operability and other similar specific details set forth hereatwere merely given for exemplary purposes. The basic arrangement issufficiently flexible to permit utilization of the relay in vastlydiflferent applications and to provide relays of extremely diiferentspecifications Without departing from the scope of the invention.

From the foregoing, it will be appreciated that the present inventionprovides an improved relay of extremely practical and economicalconstruction and assembly that is adapted to be readily actuated inresponse to energize.- tion thereof, but which will not be actuated by,or be responsive to, rapid acceleration and sharp changes inacceleration and deceleration. It will also be appreciated that thepresent invention provides an extremely compact relay of small sizeadapted for a variety of uses and installations.

While we have described what we regard to be preferred embodiments ofour invention, it will be apparent that various changes, rearrangementsand modifications may be made therein without departing from the scopeof the invention, as defined by the appended claims.

We claim:

1. In a statically and dynamically balanced relay structure, an armaturemember mounted in a given plane for pivotal movement about its centralaxis with the application of given forces at points on opposite sides ofsaid axis which are equidistant from said axis, a balanced actuatingmember on said armature extending generally transversely thereof withthe longitudinal axis thereof intersecting the armature pivotal axis,the pivotal axis of the actuator means coinciding with the armaturepivotal axis; and contact means disposed on either side of said armatureplane and equidistant therefrom and operatively associated with saidactuator member for operation thereby.

2. In a statically and dynamically balanced relay structure, a coil andcore means defining a pair of poles, the longitudinal axes of said polesbeing disposed in spaced parallel relation in a common plane, anarmature member pivotally mounted on an axis located in said plane,contact sets including movable contact members disposed on either sideof said armature and equidistant therefrom in a common plane whichintersects the first plane along a line which coincides with the pivotalaxis of said armature, and balanced actuating means for operating saidcontact sets with movement of said armature, the effective longitudinalaxis of said actuator means being mounted in the plane common to saidmovable contact members.

by said actuator means, said contact carrying'members havinglongitudinal axes disposed in parallel alignment with the longitudinalaxes of said pole members.

4. A relay comprising coil and core means presenting a pair of polemembers, the longitudinal axes of said pole members being disposed inspaced parallel relation in a common plane, contact sets disposed onopposite sides of the plane of the axes of said poles, each contact setincluding a movable lever, the longitudinal axes of said levers beingdisposed in spaced parallel relation to the longitudinal axes of saidpoles and to one another and lying in a common plane, the plane of theaxes of the levers and the plane of said pole axes intersecting oneanother, an arma-. ture operatively controlled by said pole membersmounted for rotation on an axis located on the line defined by theintersection of said planes, and actuator means disposed with itslongitudinal axis in the plane common to said movable levers operativelyconnecting said armature to each of said levers for effecting actuationthereof.

5. A relay as set forth in claim 4, in which each of said contact setsalso includes a pair of spaced stationary contacts, and a pair ofcontacts carried by each of said levers for engaging the associatedstationary contacts.

6. A relay as set forth in claim 4, including a spring positionedbetween each of said pole members and said armature for normally biasingsaid armature away from said pole members, each pole member having atapped bore therein for the reception of its associated spring, andadjustable screw means threaded in said bores for varying the forceexertion of said springs. p

7. A relay as set forth in claim 4, in which each of said contact setsincludes a mounting plate, a pair of spaced supports on said plate, aset screw adjustably mounted in each of said supports, and a contactcarried by each of said set screws, and in which said movable levercarries a pair of contacts which are disposed for engagement with saidset screw contacts.

8. A statically and dynamically balanced relay structure as set forth inclaim 4, in which each of said contact sets includes a pair of spacedstationary supports, a set screw adjustably mounted in each of saidsupports, a contact carried by each of said set screws, and a pair ofcontacts mounted on each lever for engagement with said set screwcontacts, and which includes spring means for biasing said armature awayfrom said pole faces, and adjustable means carried by said poles forvarying the biasing efiect of said spring means on said armature.

9. A relay comprising coil and core means presenting a pair of poles,the axes of said poles being disposed in spaced parallel relation in acommon plane, a pair of contact sets disposed to opposite sides of theplane of the axes of said poles, each of said contact sets including apair of substantially solidly positioned contacts disposed in spacedrelation and a flexible contact carrying lever extending between saidcontacts, the longitudinal axes of the levers of said sets beingdisposed in spaced parallel relation in a common plane, the plane ofsaid lever axes and the plane of said pole axes intersecting oneanother, an armature mounted for rotation on an axis defined by the lineof intersection of said planes, spring means between said poles and saidarmature normally biasing said armature away from said poles, andactuator means connecting said armature and the levers of said contactsets, said spring means normally biasing said armature to move the leverof each set into engagement with one of the contacts of the respectivesets and to eifect overtravel of a portion of each lever with respect tosaid one contact, said armature upon energization of said coil meanseffecting movement of said levers into engagement with the other contactof the respective sets and overtravel of a portion of each lever withrespect to said other contact.

10. A relay comprising coil and core means defining a pair of poles, thelongitudinal axis of said poles being disposed in spaced relation in acommon plane, a pair of contact sets disposed on opposite sides of theplane of said poles, an armature mounted for pivotal rotation on an axisdisposed in the plane of said poles, actuator means extending traverselyof said armature for operatively controlling said contact sets withmovement of said armature, a rectangular can enclosing said coil andcore means, said armature, said contact sets and said actuator means,and means for supporting said enclosed members with the plane of saidpoles disposed along one diagonal of said rectangular can, and thelongitudinal axis of said actuator means disposed along the otherdiagonal of said rectangular can.

11. In a relay structure, coil and core means defining a pair of poles,the axes of said poles being disposed in spaced parallel relation in afirst plane, an armature member mounted for pivotal movement betweensaid poles about a central axis and controlled by said pole members, apair of contact sets, each comprising at least one fixed and one movablymounted contact, said sets being disposed on either side of saidarmature and equidistant therefrom with the longitudinal axis of thecontact sets disposed in a second plane substantially perpendicular tosaid first plane, and contact actuator means mounted on a pivotal axislocated at the point of intersection of the first and second planes formovement by said armature member, said actuator means being interlockedwith the movable member of each of said contact sets to pre ventindependent movement of the movable contact member relative thereto, andto effect operation of said movable contact into and out of engagementwith its associated fixed contact responsive to movement of saidarmature.

12. In a relay structure, coil and core means defining a pair ofcylindrical poles having their longitudinal axes disposed in parallelrelation, each of said poles having a cutaway flat face portion thereon,an armature member having flat face portions located equidistant fromthe armature central axis, means for supporting said armature forrotation about its central axis with said armature face portions infacing relation with the pole face portions, an actuator member mountedfor movement with said armature, the longitudinal axis of the actuatormember extending generally transversely of and to either side of thearmature longitudinal axis and in balanced relation therewith, andcontact set means disposed on either side of said armature, each of saidcontact set means comprising at least one fixedly positioned contact,and a contactcarrying lever mounted as a cantilever with the free endthereof interlocked with said actuator for movement therewith, thelongitudinal axes of said contact levers being disposed in parallelrelation with the longitudinal axes of said poles.

13. In a relay structure, a balanced armature member mounted for pivotalmovement; a contact set disposed on opposite sides of said armaturemember, each set comprising at least one fixedly positioned contact, anda contact carrying lever mounted as a cantilever; a single actuatormember supported transversely of the armature to transfer armaturemovements to each of said levers; and means for effecting movement ofsaid armature member in a direction to control said actuator to move thelever of each set to bring the contact on each lever into engagementwith its associated fixedly positioned contact, and in a continuedmovement of the armature in the same direction to eifect the flexing ofthe lever ends relative to the engaged contacts so as to assureengagement of each cantilever contact with its associated fixed contacteven though the fixed contacts are normally at different spacings fromtheir cantilever contact.

14. In a relay structure, a contact assembly comprising a flexiblecontact carrying member, at least one fixedly positioned contact, aspring, an actuating member connected between said flexible contactcarrying member and said spring, said spring normally biasing saidactuating member to move said flexible contact member into engagementwith said fixedly positioned contact and effecting overtravel of aportion of said flexible contact member with respectto said fixedlypositioned contact, and adjustable means for, varying the biasing effectof said spring on said actuating member.

15. In a relay structure having a movable armature, a contact assemblycomprising a flexible contact carrying member, at least one fixedlypositioned contact, an actuating memberfor ettecting movement of saidcontact carrying member with movement of said armature, a spring fornormally biasing the relay armature and said actuating member to movethe flexible contact carrying member into engagement with said fixedlypositioned contact and to effect overtravel of said flexible contactcarrying member with respect to said fixedly positioned contact,adjustable means for adjusting said fixedly positioned contact tovarious fixed positions with respect to said member, and adjustablemeans for varying the biasing effect of said spring relative to saidactuating member.

16. In a relay structure, a pair of pole members disposed in a givenplane with the longitudinal axis thereof disposed in parallel relation,a balanced armature mounted between said poles for movement about acentral pivotal axis .with the application of given forces by said polesat opposite ends of said armature, the armature pivotal axis being inthe plane of the pole longitudinal axis, a finger carrying actuatormember associated with said armature extending laterally to at least oneside of the armature at its pivotal point, and a contact carrying memberdisposed on said one side of said armature comprising a flexible leverand at least one fixedly positioned contact, the lever being disposedwith its longitudinal axis in parallel alignment with the longitudinalaxis of said pole members and being mounted for intimate engagement ofthe fingers. of said actuator and movement thereby into and out ofengagement with said fixedly positioned contact.

17. In a relay structure, a pair of pole members disposed in a givenplane with the longitudinal axes thereof disposed in parallel. relation,a balanced armature mounted for pivotal movement about its central axiswith the application of given forces by said poles at points on oppositesides of said armature and equidistant from said pivotal axis, abalanced actuating member on said armature extending generallytransversely thereof, and contact sets disposed on opposite sides ofsaid armature, each of which comprises at least one fixedly positionedcontact,

and a contact carrying lever disposed for movement by saidagtuatin'gmember into engagement with said fixed contact and in acontinued movement of the actuator in the'same operation to be flexedabout said fixed contact in anovertravel manner, said levers havingtheir longitudinal axes disposed in parallel alignment with thelongitudinal axes of the pole members.

18. A relay structureas set forth in claim 17 in which each contact setincludes a second fixed contact, and which includes means for normallyengaging said actuator to move said lever into engagement with saidsecond fixed contact and to normally flex said lever about said secondfixed contact in an overtravel manner.

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